jika tan a=b, maka nilai (2 sinA cos A) + (cos^2A - sin^2 A)
Matematika
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Pertanyaan
jika tan a=b, maka nilai (2 sinA cos A) + (cos^2A - sin^2 A)
1 Jawaban
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1. Jawaban bapakdr
sin a = b/√(1+b²)
cos a = 1/√(1+b²)
(2 sin A cos A) + (cos²A - sin²A)
= (2 × b/√(1+b²) × 1/√(1+b²)) + ((1/√1+b²)² - (b/√1+b²)²)
= 2b/(1+b²) + (1-b²)/(1+b²)
= (2b + 1 - b²) / (1+b²)
= (-b² + 2b + 1) / (1+b³)